Stepladder



- April 18, 1944. R Ri BY 2,347,065

7 STEPLADDER Filed March 26, 1942 Patented Apr. 18, 1944 UNITED STATES PATENT OFFICE STEPLADDER Ralph Rigby, Berea, Ky. Application March 26, 1942. Serial No.436,292

' 1 Claim. (01. 228--31) My invention relates to new and useful improvements in ladders and relates more particularly to that type of ladder commonly called step ladder.

It is an object of my invention to provide a step Another object of my invention is to provide a ladder wherein vibration is prevented.

Another object of my invention is to provide a ladder which is susceptible to adjustment for varying slopes and wherein the legs are independently adjustable.

A further object of my invention is to provide a ladder which will be economical and simple to manufacture and yet which will be substantial and highly durable and efiicient in use.

Other objects of my invention and the invention itself will become increasingly apparent from a perusal of the following description and the accompanying drawing in which drawing:

Fig. 1 is a front elevational view of the ladder of my invention is an opened or operating position;

Fig. 2 is a top plan view of the opened ladder, illustrating in broken lines the path taken by the rear legs from folded to open position;

Fig. 3 is a side elevational view of the opened ladder; and

Fig. 4 is a horizontal sectional view taken on the line l-4 of Fig. 1 illustrating the angular arrangement of the legs.

The ladder of my invention consists of a frame 1 comprising side stiles or rails 2 and 3 a plurality of steps 4 and supports 5, a top step 6 and a pair of rear legs or braces l'l.

It is to be noted that the forward edge 8- of each of the steps of the ladder is of less longitudinal extent than the rear edge 9 of each step and that the step generally is of the shape of an isosceles trapezoid and hence the side edges it; and H of the step and the contacted side rails 2 and 3 form an obtuse angle with the front edge 8. To secure the steps to the ladder side rails 2 and 3, I preferably provide the braces 5, which are secured to the side rails by means of nails or the like, and disposed at an inclination to the same. Said supports underlie each step and afford a point of attachment for the step whereby said steps may be inclined to the side rails, as illustrated in Fig. 3, and disposed at an obtuse angle to the same. as illustrated in Fig. 4., The steps are preferably disposed at such an inclination to the side rails as to be parallel to the taper-ed rail ends 20. and 3d at the lower ends of the rails and 2b and ill) at the upper ends of said rails so as to be horizontal when the ladder is fully opened. Said steps are further secured to the side rails by means of nails or the like driven in through the sides of the rails.

The top step 6 is secured in similar manner to the upper ends 2b and. 3b of the side rails and this step is of greater length and width than the other steps of the ladder, covering the upper ends of the side rails and overhanging the same.

The supporting legs or rear braces 1-1, it is to be noted are secured firmly to the top of the angling side rails, bolts and wing nuts being used, in the form shown in the drawing at l2. When the ladder is folded for storage, the rear legs assume the position la shown in broken lines in Figs. 2, 3 and 4, wherein they lie snugly beside the rails 2 and 3, resulting in a compact structure requiring a minimum of space. The wing nuts retain the legs securely in either the collapsed or extended positions.

When the legs 'l-| are pushed rearwardly into a supporting position, the base of the ladder widens and hence the ladder is braced against any side vibration, a pyramidal structure being formed, each of the four supports, namely the two rear legs and the two side rails sharing an equal amount of the load imposed upon the ladder.

Further, since the legs 7-1 are independently adjustable, as shown at lb in Fig. 3, when the ladder is used on an inclined or irregular ground or floor one leg may be extended farther rearwardly than the other to compensate for the inclination or the irregularities in the surface.

It is to be noted that, regardless of the position of the legs of the ladder and regardless of their being adjusted to dissimilar positions, the ladder is at all times stable and will support the load imposed by the person using the ladder, remaining securely in the position in which it was placed and affording a sure safe footin for the person using the same. This is due largely to the angular disposition of the side rails and the equalization of the load by the four supports referred to. Hence, no dangerous side movement of the ladder occurs and the ladder is not susceptible to vibration whereby the same would be rendered unsafe.

It will be noted that the upper portions of the rear braces or legs !-I are securely maintained in contact with the upper outer faces of the side rails regardless of the positioning of said members and hence the legs must spread out laterally at the bottom, the distance between the lower ends of said legs progressively increasing as the legs are moved rearwardly with respect to the main ladder frame, due to the angular disposition of said side rails, thus bracing the ladder against any side vibrations, the rear legs are secured at a medial portion thereof by chainsor extensible means I6 and I! to the main frame of the ladder. In the form shown, this connecpoints l3 and to the rear faces of the legs 1 at l5.

The side rails 2 and 3 may be provided, a shown in broken lines in Fig. 1, with extensible feet I 8 whereb the ladder may be accommodated to various slopes of terrain. The improved action of the ladder of my invention would not be effected thereby, the extensions bein merely an addition thereto.

As best shown in Figs. 2 and 4, as the legs '!'l are moved rearwardly the inner faces of said legs form an extension of the line of angle of the outer faces of the side rails 2 and (i, and if said line be projected forwardly the lines formed by the angularly disposed side rails 2 and 3 will meet at a point marked a: which meeting point is a projection of the exact center lin of said ladder.

Although I have shown and described preferred embodiments of my invention and have shown the ladder in a form well adapted to be constructed of wood, I am aware that various other materials might be employed in constructing the ladder and various improvements and modifica tions could be made without, however, departing from the spirit of my invention and the scope of the appended claim.

I claim:

In a ladder, the combination of a pair of side rails, steps therebetween, a pair 0f braces each pivotally secured to the upper ends of one of said side rails, said steps being each provided with a forward edge of relatively less longitudinal extent than the rear edge of each said step, said step being generally of the shape of an isoscele trapezoid, the outwardly rearwardly diverging side edges of each said step being secured flush to the adjacent side rail, said side rails having'their forward or leading edges substantially closer than the rear edges of said side rails, said rear brace adapted to be moved rearwarclly with respect to said side rails, the inner faces of said rear braces forming an extension of the line of angle of the outer faces of said side rails.

RALPH RIGBY. 

